本文实例讲述了php实现的返回数据格式化类及其用法，在字符串处理中非常具有实用价值。分享给大家供大家参考。具体方法如下：

DataReturn.class.php类文件如下：

<?php 
/** 返回数据格式化类 
*  Date:  2011-08-15 
*  Author: fdipzone 
*/ 
 
class DataReturn{  // class start 
 
  private $type; 
  private $xmlroot; 
  private $callback; 
  private $returnData; 
 
  public function __construct($param=array()){ 
    $this->type = $this->exists($param,"type")? strtoupper($param["type"]) : "JSON";   // 类型 JSON,XML,CALLBACK,ARRAY 
    $this->xmlroot = $this->exists($param,"xmlroot")? $param["xmlroot"] : "xmlroot";   // xml root dom name 
    $this->callback = $this->exists($param,"callback")? $param["callback"] : "";     // JS callback function name 
 
    $format = array(); 
    $format["retcode"] = $this->exists($param,"format.retcode")? $param["format"]["retcode"] : "retcode";//retcode 对应名称 
    $format["msg"] = $this->exists($param,"format.msg")? $param["format"]["msg"] : "msg";        //msg 对应名称 
    $format["data"] = $this->exists($param,"format.data")? $param["format"]["data"] : "data";      //data 对应名称 
 
    $result = array(); 
    $result[$format["retcode"]] = $this->exists($param,"retcode")? $param["retcode"] : 0; 
    $result[$format["msg"]] = $this->exists($param,"msg")? $param["msg"] : ""; 
    $result[$format["data"]] = $this->exists($param,"data")? $param["data"] : ""; 
 
    $this->returnData = $result; 
  } 
 
  //输出数据 
  public function data_return(){ 
    ob_clean(); 
    switch($this->type){ 
      case "JSON": 
        $this->json_return(); 
        break; 
      case "XML": 
        $this->xml_return(); 
        break; 
      case "CALLBACK": 
        $this->callback_return(); 
        break; 
      case "ARRAY": 
        $this->array_return(); 
        break; 
      default: 
        $this->json_return(); 
    } 
    exit(); 
  } 
 
  //输出JSON格式数据,如有callback参数则返回JSONP格式 
  private function json_return(){ 
    header("content-type:text/html;charset=utf-8"); 
    if(empty($this->callback)){ 
      echo json_encode($this->returnData); 
    }else{ 
      echo $this->callback."(".json_encode($this->returnData).");"; 
    } 
  } 
 
  //输出XML格式数据 
  private function xml_return(){ 
    header("content-type:text/xml;charset=utf-8"); 
    echo $this->xml_encode($this->returnData,$this->xmlroot); 
  } 
 
  //输出JSON格式数据，并调用callback方法 
  private function callback_return(){ 
    header("content-type:text/html;charset=utf-8"); 
    $this->callback = empty($this->callback)? "callback" : $this->callback; 
    echo "<script type="text/javascript">
"; 
    echo $this->callback."(".json_encode($this->returnData).");
"; 
    echo "</script>"; 
  } 
 
  //输出数组格式数据 
  private function array_return(){ 
    header("content-type:text/html;charset=utf-8"); 
    echo "<pre>"; 
    print_r($this->returnData); 
    echo "</pre>"; 
  } 
 
  //XML编码 
  private function xml_encode($data, $root="xmlroot", $encoding="utf-8") { 
    $xml = "<?xml version="1.0" encoding="" . $encoding . ""?>
"; 
    $xml.= "<" . $root . ">
"; 
    $xml.= $this->data_to_xml($data); 
    $xml.= "</" . $root . ">"; 
    return $xml; 
  } 
 
  //数组转XML格式 
  private function data_to_xml($data) { 
    if (is_object($data)) { 
      $data = get_object_vars($data); 
    } 
    $xml = ""; 
    foreach ($data as $key => $val) { 
      is_numeric($key) && $key = "item id="$key""; 
      $xml.="<$key>"; 
      $xml.= ( is_array($val) || is_object($val)) ? $this->data_to_xml($val) : $this->cdata($val); 
      list($key, ) = explode(" ", $key); 
      $xml.="</$key>
"; 
    } 
    return $xml; 
  } 
 
  //判断数据是否存在 
  private function exists($obj,$key=""){ 
    if($key==""){ 
      return isset($obj) && !empty($obj); 
    }else{ 
      $keys = explode(".",$key); 
      for($i=0,$max=count($keys); $i<$max; $i++){ 
        if(isset($obj[$keys[$i]])){ 
          $obj = $obj[$keys[$i]]; 
        }else{ 
          return false; 
        } 
      } 
      return isset($obj) && !empty($obj); 
    } 
  } 
 
  //判断是否需要加上<![CDATA[]]>标记 
  private function cdata($val){ 
    if(!empty($val) && !preg_match("/^[A-Za-z0-9+$]/",$val)){ 
      $val = "<![CDATA[".$val."]]>"; 
    } 
    return $val; 
  } 
}  // class end 
?> 

demo示例程序如下：

<?php 
  require_once("DataReturn.class.php"); 
  $param = array( // DataReturn 参数 
          "type"  => "JSON", // 输出的类型 JSON,XML,CALLBACK,ARRAY 默认为 JSON 
          "retcode" => "1000", // retcode 的值，默认为0 
          "msg"   => "",   // msg 的值，默认为空 
          "data"  => array( // 要输出的数据 
                  "id"   => "100", 
                  "name"  => "fdipzone", 
                  "gender" => 1, 
                  "age"  => 28 
                 ), 
          "format" => array( // 输出的数据key格式,默认为 retcode,msg,data 
                  "retcode" => "status", 
                  "msg"   => "info", 
                  "data"  => "result" 
                 ), 
          "xmlroot" => "xmlroot", // 当type=XML时,XML根节点名称，默认为xmlroot 
          "callback" => "callback" /* 回调方法名称 
                          type=JSON时，默认为空，如不为空，则输出callback({data}); 
                          type=CALLBACK时,默认为callback，自动调用页面JS回调方法 
                       */ 
  ); 
  $obj = new DataReturn($param); // 创建DataReturn类对象 
  $obj->data_return();      // 按格式输出数据 
?>

希望本文所述对大家php程序设计的学习有所帮助。